Question 1127286: A jar contains half dollars and quarters there are 30 coins in all the total value of coins is $8.75 how many quarters are in the jar Answer by addingup(3677) (Show Source):
You can put this solution on YOUR website! Let half dollars be d and quarters be q
d + q = 30 thus, q = 30 - d
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0.5d + 0.25q = 8.75 substitute for q:
0.5d + 0.25(30 - d) = 8.75
0.5d + 7.5 - 0.25d = 8.75
0.25d = 1.25
d = 5 so there are 5 half dollars in the jar
Therefore, there are 30 - 5 = 25 quarters in the jar
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Check:
25 x 0.25 = 6.25
5 x 0.5 = 2.5
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Total . . 8.75 Correct
